Pulley friction drive



Jan. 17, 1956 F. M. FENCE 2,730,905

PULLEY FRICTION DRIVE Filed Aug. 10, 1953 FRDER/CK M. FENCE,

. INVENTOR.

HUEBNER, BEEHL 5e,

:22 woma a: HERZ/G, 52 ATTORNEYS.

. a BYUMT 99-44-0 10 United States Patent PULLEY FRICTION DRIVE Frederick M. Pence, Whittier, Califl, assignor, by mesne assignments, 'to Norris-Thermador Corporation, Los Angeles, Calif., a corporation of California Application August 10, 1953, Serial No. 373,293

1 Claim. 01. 74-206) This invention relates to a pulley friction drive, and more particularly to a pulley drive mechanism in which a pulley is simultaneously in engagement with a belt and with a friction wheel which engages a portion of the pulley. This invention has particular adaptability to, and is shown in this instance in connection with, an evaporative type air cooler.

It is an object of this invention to provide means whereby a rotating pulley may serve as the convenient source of power for a shaft to be rotated by direct contact or engagement with the pulley.

It is another object of this invention to provide a pulley which will fulfill a double duty in serving not only as a means for engagement by a driving belt but also a means for engagement with a friction wheel mounted to an independent shaft.

It is a further object of this invention to eliminate the necessity for an independent driving motor for the recirculating pump of an evaporative type air cooler.

In accordance with these and other objects which will become apparent hereinafter, a preferred form of the instant invention will now be described with reference to the accompanying drawings, wherein:

Fig. 1 is an elevation view partly broken away showing an evaporative type air cooler embodying the present invention.

Fig. 2 is an elevation taken at right angles to the elevation of Fig. 1 with certain parts being broken away.

Fig. 3 is a fragmentary cross-section showing the pulley drive mechanism of the instant invention.

Referring to the drawings, 11 designates an evaporative air cooler housing having a pan or bottom 12 adapted to hold a pool of water. The sides 13 of the housing 11 are louvered, as shown at 14, to admit air into the housing. Immediately inside the sides 13 is a wall structure 16 formed of filter-like material such as excelsior or like material.

The purpose of the excelsior wall 16 is to temporarily retain and be wetted by streams of water as they drop downwardly through the wall structure 16 from a slotted trough 17, disposed horizontally along the top edge of each wall structure 16.

Within the housing 11 is an air impeller including a scroll casing 18, the outlet 19 of which emerges from the housing 11 and is connected by a suitable conduit (not shown) to the region to be cooled. Within the casing 18 is rotatably mounted a blower wheel 21, which in rotation causes air to be drawn in through the inlet opening 22 of the scroll casing 18 and out the outlet 19. The blower wheel 21 is secured to a substantially horizontal shaft 23 journaled in bearings 24, forming part of the casing 18.

Secured to one end of the shaft 23, within the housing 11 but outside of the casing 18, is an impeller pulley 26 constructed in accordance with the instant invention. Mounted to a bracket 27 within the housing 11 is an electric motor 28 having a pulley 29 which is engaged with the impeller pulley 26 by means of a belt 31.

2,730,905 Patented Jan. 17, 1956 The pulley 26 consists essentially of a circular disc forming the body of the pulley and having a wedge-shaped groove 32 around the periphery thereof, which receives the correspondingly wedge-shaped belt 31.

The pulley 26, in accordance with the present invention, is characterized by a flange 33 which extends obliquely outward from one peripheral edge only of the disc body. The flange 33 starts adjacent the groove 32 and extends first directly away from the belt 31, as shown at 34, and then extends obliquely away to form a conical surface 35. The apex of the cone on which the surface 35' lies is intersected by the axis 37 of the cone, as shown by the point 38.

Resting on the bottom 12 is a water circulating pump 41 having an impeller portion 42, the greater portion or all of which is disposed beneath the level of the pool of water 43 in the bottom 12. The outlet 44 of the pump 41 is connected by means of flexible tubing 46 to a central fitting 47 located at the ceiling of the housing 111. From the fitting 47 the water flows to the three excelsior walls 16 by means of three horizontal pipes 48, the ends of which empty into the troughs 17. Thus when the pump is in operation, water is continuously lifted from the pool 43 through the tubing 46 up to the troughs 17, from which it flows through the slots in the troughs down through the excelsior laden walls 16.

Extending upward from the impeller portion 42 of the pump 41 is a framework 49, which serves to support for rotation a vertical impeller shaft 51. The shaft 51 terminates in a wheel 52 having a friction ring or tire 53, which is preferably made of rubber or equivalent thereof. The rubber ring 53 is in frictional engagement with the conical flange 35 of the pulley 26.

The pump 41 is pivotally mounted on short trunnions 54 and counterweighted slightly so as to tend to rotate counterclockwise in Fig. 2. In this way there results a continuous bias tending to keep the friction wheel 52 continuously pressed into frictional engagement with the flange 35.

Provision of the friction wheel 53, driven by the flange 35, obviates the necessity for a separate electric motor to drive the vertical shaft 51 of the pump 41.

In order to minimize wear on the rubber ring 53, the angle of the conical surface of the flange 35 is selected so that the point of intersection between the axis 56 of the shaft 51 and the axis 37 of the pulley shaft 23 coincides with the apex 38 of the conical surface, as shown in Fig. 3.

In order to effect the desired speed ratio between the shaft 23 and the shaft 51, the ring 53 must be of given diameter with respect to the pulley 26. In the example illustrated in Fig. 3, the desirable positioning of the pump 41 on the bottom 12 causes the ring 53 to be so disposed that the portion 34 of the flange 33 is required in order to offset the outer flange portion 35 the proper amount. Under certain circumstances it is possible to create the drive flange 35 by simply extending it. directly outward from the groove 32 and adjusting the angle of the conical surface to fit the criterion set forth above.

In accordance with the present invention, it is preferred to form the pulley 26 of a pair of circular discs 57 and 58 which are secured together face to face as by spot welding, each disc having previously stamped so as to form around the edge thereof the respective flanges 33 and 59. The disc 57 is appreciably larger than the disc 58 in order to provide for the formation of the extra flange portion 35.

As air is drawn into the housing by rotation of the blower wheel 21 and impelled through the outlet 19, the water in the walls 16 is evaporated, cooling the air correspondingly. The water thus evaporated from the pan 12 is replaced by inflow of water through an inlet pipe 61 and through a valve 62 actuated by a float 63. In this manner the level of the pool of water 43 is kept constant at all times.

shaft 23ca use's rotation of the blower wheel 21, which, as

explained hereinbef'ore, draws air in through the louvered Walls 13 and impels it through the outlet conduit 19, and

i also efiects operation of the pump '41 through the frictional coupling between the flange 35 on the pulley 26, and the ffrictio'n wheel 52 on the end of the pump shaft 51.

While the instant invention has been shown and described herein in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein but is'to be accorded the full scope of the claim.

What is claimed is:

A'pulley adapted to be driven by a belt and to frictionally drive a shaft'dispos'ed substantially at right angles to the axis of the pulley, comprising: a pair of circular discs secured together face to face, each of said discs being bent outward around its edge to form an oblique flange, said disc flanges forming therebet-ween the pulley groove for receiving a drive belt, one of said discs being larger in diameter than the other of said discs, the flange on said one disc continuing outward and lying on the surface of a cone, said cone surface being adapted to engage a friction drive wheel on said shaft disposed substantially at right angles to'the axis of the pulley.

References Cited in the file of this patent UNITED STATES PATENTS 941,857 Cohn Nov. 30, 1909 1,544,756 Hoover July 7, 1925 2,185,529 Sullivan Jan. 2, 1940 2,185,530 Sullivan Jan. 2, 1940 2,186,290 Gordon et al. Jan. 9, 1940 2,387,473 Spitzka Oct. 23, 1945 2,412,078 Breckenridge et al. Dec. 3, 1946 2,606,009

Long AugQS, 1 952 

